Primary pulmonary artery neoplasms are rare and lethal. Those involving the pulmonary valve are even rarer with only a few reported cases in the literature. The poor prognosis of these neoplasms, despite attempted multimodal therapy, is largely related to delay and difficulty in diagnosis. The case of a 53-year-old woman is described who within one month of suddenly developing shortness of breath was found to have a mass arising from the pulmonary valve and extending through the pulmonary vasculature, requiring extensive surgical resection. She died two weeks postoperatively. The morphological findings of this primary pulmonary artery sarcoma are presented. Diagnosis, treatment, prognosis and literature are reviewed, and consideration of this tumour in the differential diagnosis of other pulmonary diseases is emphasized.